The optimal cigarette nicotine content that would reduce tobacco dependence while still alleviating nicotine craving and withdrawal symptoms and the effects of nicotine content reductions on large smoker subpopulations are critical issues that could inform FDA tobacco product regulation. The goal of this project is to test the effects of reduced nicotine content cigarettes in 40 young adult daily smokers (aged 18-25 years). Investigators will compare the responses to smoking research cigarettes with four levels of nicotine content (<0.05, 0.1, 0.282, or 0.68 mg nicotine) and preferred cigarette brand smoked as the first cigarette of the day in the context of the following specific aims: (1) to obtain self-report ratings of the smoking experience, relief of craving and withdrawal, and affect; (2) to measure how the different cigarettes affect attention and neural biomarkers of withdrawal and executive functioning; and (3) to measure how the different cigarettes affect neural biomarkers of craving and its regulation. Functional magnetic resonance imaging (fMRI) will be used to provide a brain biomarker of response to the different nicotine yields, which can further elucidate subjective and cognitive effects. Findings will provide novel data that may inform decision-making regarding a standard for cigarette nicotine content.